Blockchain Platform Engineer - Web3 & Smart Contracts

Quantum Technologies LLC; Jersey City (NJ); On-site; USD 75,000 - 107,000; Full time

Job summary

Quantum Technologies LLC in Jersey City, NJ, seeks a Blockchain Engineer to design and build Web3 platform services for tokenization, connectivity, and asset management. The role includes integrating with Ethereum/EVM, Hyperledger Besu, Canton/Daml, and Layer 2 solutions in enterprise systems.

The contract runs for 8 months with potential extension and requires familiarities with JSON-RPC, WebSocket, and smart contract interactions across on-prem and cloud environments.

Responsibilities

• Design and build reusable Web3 platform services for tokenization, blockchain connectivity, wallet integration, and token lifecycle management.
• Develop backend services that interact with blockchain nodes, smart contracts, custody platforms, signing systems, and off‑chain enterprise applications.
• Build abstraction layers supporting Ethereum/EVM, Hyperledger Besu, Canton/Daml, Layer 2 solutions, permissioned networks, and consortium blockchains.
• Implement blockchain integrations using JSON-RPC, WebSocket subscriptions, contract queries, transaction submission, status tracking, and event processing.
• Engineer and maintain connectivity solutions for Besu, Ethereum-compatible networks, and permissioned EVM ecosystems.
• Support Canton/Daml workflows including connectivity, authorization, lifecycle management, and workflow integration.
• Manage Daml application packages including deployment, versioning, validation, installation, and production enablement.
• Design, develop, integrate, and review smart contracts for tokenized assets and programmable workflows.
• Build interaction frameworks for ABI encoding/decoding, transaction simulation, calldata generation, and contract state management.
• Establish engineering standards for smart contract development, testing, deployment, governance, rollback planning, and production releases.
• Implement smart contract security best practices including threat modeling, static analysis, fuzz testing, and secure deployment pipelines.
• Integrate wallet, custody, signing, and authorization platforms to support asset management and transaction workflows.
• Design transaction orchestration services covering validation, routing, signing, submission, tracking, exception handling, and audit logging.
• Develop address management, transaction limits, allowlists, approvals, signing policies, and governance mechanisms.
• Collaborate with platform, infrastructure, security, and operations teams to deliver scalable Web3 solutions for enterprise digital assets.

Job description

Quantum Technologies LLC in Jersey City, NJ, seeks a Blockchain Engineer to design and build Web3 platform services for tokenization, connectivity, and asset management. The role includes integrating with Ethereum/EVM, Hyperledger Besu, Canton/Daml, and Layer 2 solutions in enterprise systems.

The contract runs for 8 months with potential extension and requires familiarities with JSON-RPC, WebSocket, and smart contract interactions across on-prem and cloud environments.